Project Gutenberg is the primary online repository for public domain book text. The size and quality of the collection is staggering. So it's no surprise that the availability of these books is often one of the driving motivations for purchasing an e-ink electronic book reading device. One can get many of these texts already formatted for your device at ManyBooks. This would be the natural first place to look for iLiad owners, or Sony Librie owners as well. And outside of the e-ink domain, there are also iPod notes formats and pda formats as well.

But suppose the book is not available already packaged up in pretty form for the iLiad? You could certainly just read the text form, but you might just want to create an iLiad version yourself. If that's what you want to do, then be sure to check out the very thorough conversion tutorial over at TeleRead Blog.

In this step by step tutorial of converting from Gutenberg texts to iLiad-formatted pdfs, Branko Collins guides you through requirements (it looks to me like you don't have to be on Windows OS), acquisition of the texts, reformatting them, adding page numbers and producing the final result.
Branko points out that the process is also flexible enough to support creation of other e-book formats or even paper books from the pdfs.

This is not the sort of thing that you will want to do if you just want to read immediately. But if you want to produce a quality document for a better reading experience, this might just be the ticket for you. It may also help you to understand why a publisher might charge customers to offer a nicely created public domain e-book. An e-book is more than the words contained within it.

As we find people starting to invest the time to create well produced public domain (or privately authored) e-books, we'll also have to start discussing how these e-books can best be shared with the world. I'm not sure what ManyBook's policies are with respect to submissions, but I do know that if this work is invested into creation of e-books, the results deserve to be shared with all!